The present invention relates to an opening filling apparatus and a manufacturing method of a semiconductor device by using the same, and more particularly, to an opening filling apparatus which can improve a filling characteristic by filling an opening such as a trench or a contact hole with centrifugal force and a manufacturing method of a semiconductor device by using the same.
As a semiconductor device is highly integrated, a contact is decreased in dimension while a device isolation region used for insulating one device from another is decreased. Therefore, when a trench for isolating each device or a contact hole for connecting conductive layers is formed, it is difficult to fill the trench or the contact hole without a void. Currently, a method for filling the trench or the contact hole without the void is under study.
Referring to FIGS. 1A through 1C, disadvantages of the conventional method for filling a trench will be explained.
In FIG. 1A, reference numeral 10 denotes a semiconductor substrate, 15 denotes an insulating layer, 20 denotes a void formed due to a poor step coverage.
In general, for isolating one device from another, a insulation material, for example, an oxide is deposited on semiconductor substrate 10 by using the chemical vapor deposition (CVD) method, thereby forming insulating layer 15 for filling a trench formed on semiconductor substrate 10. At this time, a void 20 is formed inside the trench due to a poor step coverage caused by the high-integration of the semiconductor device. As the succeeding heat treatment process is performed, the surface area of void 20 is decreased in size and therefore round hole-shaped void 25 is formed inside the trench (refer to FIG. 1B).
FIG. 1C is a scanning electron microscope (SEM) photograph of the hole-shaped void generated in the actual manufacturing process. Since the SEM photograph of the void is taken after the oxide stain treatment for controlling a contrast, the void is shown in larger size than the real one.
When an etching margin is too small, void 25 is exposed in the etching step and the exposed region is then filled with gate material, so that a gate stringer is generated or undesired impurity is doped into the surface of the void exposed at the ion-implantation. Therefore, the oxide layer cannot completely function as a device isolation region.
Referring to FIGS. 2A and 2B, disadvantages of the conventional method for filling a contact hole will be explained.
In FIG. 2A, the reference numeral 50 denotes a semiconductor substrate, 55 denotes an insulating layer where a contact hole is formed, and 60 denotes an interconnection layer for forming a contact hole.
The interconnection layer 60 is formed, for example, by depositing aluminum. In this case, however, a poor step coverage occurs as the contact hole is decreased in dimension due to a high-integration. Also, an agglomeration phenomenon that aluminum is conglomerated on the contact hole occurs in the succeeding heat treatment process, thereby causing a poor contact hole problem (refer to FIG. 2B).